«Whispering X.Gate» – a X.25 API Gateway

# Problem statement
Owing to the too new, too soon, too unproven and too unreliable nature of the newfangled «TCP/IP» (and, if lucky, UDP) protocol, recent industry surveys have pointed to numerous teething problems with the hipster networking protocol that has been posing untold troubles in establishing new network connections to API Gateway products that are deemed to solve real business problems, have instead become inundated with incessant and pesky 4xx, 5xx and 419 «I'm not a teapot» HTTP errors.
To answer innumerable cries for help and to silence of incessant streams of calls for perdition, herein I present a solution and a result of multiple sleepless nights and painstaking work that blends the magic of the time proven, very exceptionally solid X.25 networking protocol that solves a multitude of pesky problems and nuisances of the bohemian, so called «TCP/<no matter what P – you are not getting it anyway> protocol – once and for all.

Enter «Whispering X.Gate».

# «Whispering X.Gate» – a X.25 API Gateway

## Executive summary
«Whispering X.Gate» transforms the challenges of the X.25 and PSTN network into unique selling points. With AI and ML™® voice integrations, robust preemptive error correction, and a keen focus on user experience, the X.25-based «Whispering X.Gate» API Gateway becomes an intriguing blend of time proven and new, reliably serving a vast niche in a dedicated market segment.

## Core features
* Virtual circuit multiplexing: «Whispering X.Gate» leverages the concept of X.25 virtual circuits to maintain multiple virtual circuits per client, allowing for efficient separation of different types of API requests.
* Reliability: «Whispering X.Gate» ensures high reliability for API requests and responses utilising one of the X.25's strengths which is its built-in error correction – errors are anticipated and are preemptively corrected, even before occurring.
* Rate adaptation: Given the often slower and less reliable nature of PSTN connections, «Whispering X.Gate» incorporates adaptive rate controls. It can modulate data throughput according to the current quality of the PSTN link as well as according to the remaining budget of the project. FDMA, TDMA and CDMA modulation types, 5G, 5½G and 5¾G and mobile edge computing are supported out of the box.

## Gateway architecture
It is sublime.
* X.25 interface module: This is the core module that interfaces with the PSTN and handles the X.25 protocol, setting up and tearing down virtual circuits. Physical connection destruction tools (rakes, shovels and a small digger) are supplied with the product – to disconnect pesky and mischief clients on demand.
* API processing layer: This layer usually (dictation speed depending) understands and processes incoming API requests, passing them to the appropriate services and generating responses.
* Reliable service connectors: Modular connectors that link the gateway to various backend services. They are responsible for translating the API request to the format understood by the service. AI and ML™® assisted voice transcription is available and is enabled by default. Once a client has connected to a «Whispering X.Gate», it can never disconnect – resilience is built into the service connector from the ground up (unless damaged by excavation works).
* Progressive responses: For long-wait API calls, instead of keeping the client waiting, the gateway can send intermittent updates, giving API clients a sense of progress (whatever that means to them).
* Latency problem solved: Whilst the original X.25 might have higher latency due to its error-correction features and PSTN origin, «Whispering X.Gate» uses aggressive caching and AI and ML™® prediction and hallucination algorithms to preemptively respond to common API requests – API clients are guaranteed to receive a response even before they send a request.
* Billing and metering module: Since X.25 and PSTN imply metered billing, the dedicated, state of the art billing module keeps track of connection durations and data volumes, generating bills for clients on the fly. Business units and projects are back-charged in real time obviating the need for cost tags. American Express is supported. Projects that have run out of funding are cut off from the services in real time with a predefined, standard «The API you have dialled is not available to converse with, please contact our friendly billing department for assistance» error response – to contain excessive costs and budget overruns.
* Tiered subscription model: Given the potentially higher cost of PSTN connections, «Whispering X.Gate» offers a tiered subscription model, where clients can pay for priority circuits or higher bandwidth. The clients can downgrade their subscription tier at any time by dialling the «000» API on the «Whispering X.Gate» API gateway.

## Client architecture
* X.25 client interface: Allows the application to connect to the X.Gate via a PSTN-like connection via the most cordial and most harmonising «Dial a Gate» X.25 API client library (the «Dial a Gate» X.25 API client library design and its redeeming features are presented is a separate section further down below).
* API request composer: A user-friendly tool for building API requests, managing virtual circuits, and handling verbal complaints.
* Circuit manager (can be a full time or a part time position): Manages multiple virtual circuits, deciding when to open, reuse, or close them (sometimes assertively).

## Enhanced features
* Voice assistance: Given the venerable PSTN heritage, «Whispering X.Gate» also incorporates AI and ML™® assisted voice responses for certain types of API's, blending the worlds of acoustics and data.
* Fallback mode: If the data connection is poor, the «Whispering X.Gate» gateway switches to an audio mode, gently whispering data in API Gateway responses as audio-encoded, allowing for basic connectivity even under most challenging conditions. ML induced hallucinated responses are provided out of the box and are free of charge.
* PSTN gateway interconnect: Allows for the interconnection of multiple «Whispering X.Gate» gateways via PSTN, enabling distributed API endpoints for global reach hence fostering the sentience and the rise of the first SkyNet. «Whispering X.Gate» API gateways can also chat and gossip with their neighbouring «Whispering X.25» sisters during off-peak times.
* Service prioritisation: Using X.25's flow control and Quality of Service (QoS) features, «Whispering X.Gate» can prioritise certain types of API requests over others – less important API requests are silently ignored.

Since no API gateway is useful on its own, a user friendly client is required – to encourage (via persuasion or via subversion) API clients to connect to and use it. The «Whispering X.Gate» comes with batteries very user friendly API client library included.

# «Dial a Gate» – an unprecedentedly friendly and outgoing API client library

## Executive summary
«Dial a Gate» X.25 API gateway client library incorporates and integrates rotary dials to harness the simplicity and robustness of dialling, providing a tactile interface for setting up new API PSTN connections and virtual circuits with a «Whispering X.Gate» X.25 API Gateway.

The library is well on track to be open-sourced in 2035.

## API client library helpers
* Dual rotary dials: The «Dial a Gate» X.25 API gateway client comes with a device with two rotary dials. One is dedicated to selecting the desired API endpoint (like selecting an API «number»). The second dial is for setting up and managing virtual circuits.
* Connection indicator: A series of LED lights or a screen that provides visual feedback. As users dial, each rotation corresponds to a number, which can be visualised on this indicator. Huge and unwieldy OLED screens littering the precious office space are no longer necessary and can be replaced (for real-time «Whisper X.Gate» API Gateway monitoring) with a single, wall-sized switchboard that also looks cool.
* Auditory feedback: To enhance the tactile experience, the «Dial a Gate» API client provides a series of click sounds and connection tones reminiscent of time proven telephones.

## Rotary dial API operations
* Dialling API endpoints: Different numbers correspond to different API endpoints. For example, dialling «01» could connect to the OAuth 8½ compliant «User authentication» endpoint, while «02» might access «Data retrieval» and, lastly, dialling «03» erases the previous API response from existence.
* Virtual circuit management: The second dial can:
    * Set up a new virtual circuit (by dialling a specific number, say «9» – configurable, free of charge).
    * Close an existing virtual circuit (by dialling another number, say «0» – configurable, at an extra cost).
    * Dial a sequence to switch between active virtual circuits.

## Enhanced features
* Dial memory: A button (or a switch – configurable at the order placement time) allows users to save their most frequently dialled API endpoints and virtual circuit configurations. This is a quick way to re-establish commonly used circuits.
* Voice feedback: Upon successful dialling an API, a voice can confirm the connection. E.g., «You are now connected to the User Authentication Endpoint».
* Dial lock: To prevent unintended dialling or virtual circuit changes, a physical lock can be engaged, ensuring no inadvertent alterations.

## User experience
The user experience is wonderful and dreamlike.
* Tactile feedback: The rotary dial provides a tangible connection to the confusing digital world, giving users the satisfaction of manually dialling their desired configurations.
* Error handling: If a user dials an incorrect or non-existent API endpoint, the auditory feedback provides a distinct error tone. The connection indicator might flash or show an error symbol.
* Dial directory: No more confusing API documentation portals – just like phonebooks, «Dial a Gate» clients come with a printed directory of common API endpoint numbers and virtual circuit operations.

## Application scenarios
* Debugging and testing: Developers can use the «Dial a Gate» X.25 API Gateway client library to manually set up connections and virtual circuits, making the debugging process more hands-on.
* Market appeal: For enthusiasts or those craving a touch of nostalgia, the «Dial a Gate» offers a unique, pensive and hands-on way to interact with aging digital systems.
* Education and training: The «Dial a Gate» X.25 API Gateway can serve as a teaching tool, showing new generations what reliability and reliable network connections actually look like and how they work (unlike in TCP/IP where everything is based on hopes and oftentimes unfulfilled promises), whilst simultaneously teaching them about the concepts of API's and virtual circuits.